Sure, if you stay out of the broader Lemmy and stick to niche subs, you'll likely see more people that go to those niche subs. It's not that you can't find Communists or Anarchists on Reddit, they just tend to stick to their subs, while on Lemmy Communists and Anarchists are dominant in the bigger subs.
Cannot say I have really noticed any more than I did when on Reddit.
Believe me, it's very noticeable. Perhaps you conflate liberals with Communists and Anarchists?
More likely depends on your subscriptions. Mine are mostly tech related and development.
Sure, if you stay out of the broader Lemmy and stick to niche subs, you'll likely see more people that go to those niche subs. It's not that you can't find Communists or Anarchists on Reddit, they just tend to stick to their subs, while on Lemmy Communists and Anarchists are dominant in the bigger subs.